The present invention relates to a method for capturing three-dimensional data of an area of space, comprising the steps of:                providing a laser scanner having a transmitter and a receiver,        sending out a plurality of measuring beams by means of the transmitter to a plurality of measuring points in the area of space,        receiving a plurality of reflected beams which are reflected by the measuring points, and        determining a plurality of distances to the plurality of measuring points as a function of the reflected beams.        
The invention also relates to an apparatus for capturing three dimensional data of an area of space, comprising a laser scanner having a transmitter and a receiver, the transmitter being configured for sending out a plurality of measuring beams to a plurality of measuring points in the area of space, the receiver being configured for receiving a plurality of reflected beams which are reflected by the measuring points and for determining a plurality of distances to the plurality of measuring points as a function of the reflected beams.
Such a method and such an apparatus are known, for example, from DE 103 61 870 B4.
This document discloses a laser scanner comprising a measuring head which holds a rotor rotatably supported. The rotor is rotated about a horizontal axis whilst sending out a plurality of laser beams. Due to the rotation of the rotor, the laser beams are sent out into a plurality of directions in space which cover an elevation angle of 270° or more. In addition, the measuring head is rotated about a vertical axis so that the laser beams sent out almost completely scan the surrounding area of space. In the measuring head, a receiver is arranged which receives the reflected beams reflected from object points in the area of space and which determines the distances to the object points by means of a difference in delay time between the beams sent out and the received beams. In addition, the receiver generates for each measuring point a gray scale value which depends on the intensity of the reflected measuring beam. Altogether, this known laser scanner can be used for recording a three-dimensional image of an area of space, the plurality of gray scale values producing an all-round image which is comparable to a black/white recording of the area of space. In addition, a distance information item is provided for each measuring point so that the area of space can be examined more accurately, surveyed and/or documented later by means of the recorded data. A typical application for such a laser scanner is the surveying of factory halls in which, for example, a new production line is to be planned and set up. In another known application, such a laser scanner is moved through a tunnel tube (if necessary without rotation about the vertical axis) in order to check, e.g., the state of the tunnel and determine the clear width at every point in the tunnel.
In principle, such a laser scanner is suitable for capturing three-dimensional data of any area of space which is bounded by objects such as walls or natural obstacles. The relatively fast and extensive data acquisition including an “optical image” of the area of space in an all-round view also allows such a laser scanner to be advantageous for forensic applications, i.e. the coverage and documentation of crime scenes. However, forensic coverage of a crime scene requires further information which cannot be supplied by laser scanners hitherto known. This includes primarily information about the location and the course of bullet channels produced when a projectile penetrates into a wall or into another obstacle.
For the forensic coverage of bullet channels, rods marked with colours are used today which rods are inserted into a bullet channel in such a manner that a proximal end of the rods protrudes from the entry opening of the bullet channel. These rods can be used for identifying the orientation of the bullet channel. Suitable rods are offered, for example, by the Lightning Powder Company, Inc., 13386 International Parkway, Jacksonville, Fla. 32218, USA.
Against this background, it is an object of the present invention to improve a method and an apparatus of the type initially mentioned in order to open up new applications. In particular, it is an object of the invention to facilitate the forensic data capture of an area of space.